Lagoiski

Q: 27 iMac (2012) crashes and requires smc reset to turn on

My late 2012 iMac, i7 16gig RAM 27 inches keeps shutting down. It looks like as if it was unplugged. Happens randomly. Sometimes while playing Diablo 3, surfing facebook or using iphotos or other apps. Seems to not crash if just left on overnight and not been used.

 

In order to turn it on again I have to unplug it from the power line for like 30 seconds, only then it starts.

 

I have the settings set to restart on power failure, but it does not.

 

Happened a few times a few months back. I have installed a surge protector and it worked fine for like a month or two. However last 2 days it has shut down like 10 times...

 

Help would be greatly appreciated. I suspect hardware failure.

iMac (27-inch, Late 2012), iOS 7.1.1

Posted on May 5, 2014 9:44 PM

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Q: 27 iMac (2012) crashes and requires smc reset to turn on

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  • by UKscottyGB,

    UKscottyGB UKscottyGB Feb 14, 2016 12:35 AM in response to AlexPoirier
    Level 1 (4 points)
    Feb 14, 2016 12:35 AM in response to AlexPoirier

    I've got my iMac back with a new power supply board fitted & replacement power cable. It's been running for 3 days now & has not shut down once. I had it repaired at my local Apple Authorised Service Dealer (not at Apple Genius), who have been gr8! They ran hardware diagnostic tests on the repaired iMac & could not find any faults. I have to be fair & say that Apple have repaired the iMac each time it's developed the (same) fault but my confidence with this particular iMac running fault-free is low.

    I will keep you updated if the fault reappears or indeed if it completely disappears.

  • by Lisino,

    Lisino Lisino Feb 15, 2016 3:48 AM in response to UKscottyGB
    Level 1 (0 points)
    Feb 15, 2016 3:48 AM in response to UKscottyGB

    This thread has been invaluable. I have this same late 2012 model. Bought second hand in 2013. Thank you everyone for your advice and tips. I took my Mac to the Apple Store last week. Following advice from this thread I made sure my Mac had been running all day before I took it in and I had a diary of all the times it shut down - last time was one hour before my appointment. It actually shut down during a diagnostic at the Genius Bar. With no arguments, no warranty and no Apple Care they replaced the logic board (graphics card is integrated on this board the Genius informed me) and I paid for a new hard drive which showed a fault. We agreed the HD fault was a separate issue. Because of UK consumer law I did not have to pay for the logic board and labour. I felt the service was excellent and was really pleased.


    That was the good news. The bad news is that the same fault happened again last night – twice – after having been on for three days mostly in sleep mode. Going back in on Saturday to discuss it again, with my new diary entries of shut downs/power-offs.

  • by Lisino,

    Lisino Lisino Feb 15, 2016 4:06 AM in response to Robert van Dongen
    Level 1 (0 points)
    Feb 15, 2016 4:06 AM in response to Robert van Dongen

    Robert van Dongen has replacing the power unit done the trick  for you?

  • by Redbridge13,

    Redbridge13 Redbridge13 Feb 16, 2016 7:03 AM in response to Lisino
    Level 1 (0 points)
    Feb 16, 2016 7:03 AM in response to Lisino

    I can't speak for Robert, but after four trips to the Apple Store, one futile logic board replacement, two futile hard drive wipes and finally a power supply replacement, the iMac hasn't shut down on me.  I'm still slowly ramping up the work I do on it, but at least it's not instantaneously shutting down as it had before.  I'm still horrified that even though it hasn't shut down yet that the defect is still present and just working its way through amother power supply.

     

    I'll keep everyone posted but thus far the power supply replacements have had the best immediate results.  Furthermore I've informed every Apple rep of this thread though none have taken much interest in it.  I'd advise you all to do the same. 

  • by simonafromroma,

    simonafromroma simonafromroma Feb 16, 2016 8:51 AM in response to Lagoiski
    Level 1 (0 points)
    Feb 16, 2016 8:51 AM in response to Lagoiski

    Thanks everybody for keeping us posted.

    So the bad capacitor theory is gathering some steam, and this is comforting somehow.

    Apple are you there??? Can someone give us some support on this?

  • by Krishna Iyer,

    Krishna Iyer Krishna Iyer Feb 17, 2016 6:39 AM in response to vanstar sydney
    Level 1 (0 points)
    Feb 17, 2016 6:39 AM in response to vanstar sydney

    Similar problem except the shutdown happened only once and the iMac never recovered. Had to change the logic board which is costing me $500+. How can I trust Apple after this? This machine has Apple's HW and Apple's SW. So why the heck should I have to pay for their faulty build? This *****!

     

    The whole premise of Apple products being expensive and non-repairable is based on controlling the HW and SW, to provide a great user experience. So when it fails, Apple has to OWN the full responsibility and replace the system - no questions asked.

     

    Krishna

  • by Tambikerhiker,

    Tambikerhiker Tambikerhiker Feb 17, 2016 2:55 PM in response to Lagoiski
    Level 1 (0 points)
    Feb 17, 2016 2:55 PM in response to Lagoiski

    Same problem, same make, model and year. Had it to Apple three times. Like others, they were unable to replicate even after keeping the unit the third time for a week. I told them to look at these threads so they'd acknowledge it is not an isolated incident. In their infinite wisdom the Genius Bar started to blame my home office setup and wanted me hire an outside consultant to review it. As if I or any of us need someone to look at how we plug in our Macs! It was actually quite insulting. I've checked the power at the moment of shutdow at both ends and there is no and never was an interruption. Funny thing, after the third visit the problem vanished for a few months but now shows up nearly on a daily basis. This makes one wonder if the simple act of physically moving the machine causes something to happen to temporarily resolve the issue. This could explain partially why so many of us have taken out units in with Apple unable to replicate the problem. Seriously does anyone know a good class action attorney? Apple avoids any comments here or any official acknowledgment as they certainly realize this could lead to a costly recall and bad PR, God forbid! I'm checking with the FTC. Something needs to be done to make this right for us!

  • by Redbridge13,

    Redbridge13 Redbridge13 Feb 17, 2016 3:15 PM in response to Tambikerhiker
    Level 1 (0 points)
    Feb 17, 2016 3:15 PM in response to Tambikerhiker

    One of the things we seem to have discovered on this thread, and that allowed me to finish a project on the iMac before taking it in for repairs, is that if you unplug it for an extended time, say overnight, it usually stretches the amount of time that the iMac will run before the problem resurfaces.  I think this could be the issue you dealt with.  It also seems common that this fix only works for a while and the interval time before shutting down reduces over time.

  • by Tambikerhiker,

    Tambikerhiker Tambikerhiker Feb 17, 2016 3:30 PM in response to Redbridge13
    Level 1 (0 points)
    Feb 17, 2016 3:30 PM in response to Redbridge13

    Yes, I went through nearly the entire thread and perhaps unplugging it each night is a bit helpful. However, that is a side issue. The real issue is that this model/year is inherently defective and Apple is not acknowledging what for them would be an expensive problem to deal with. Instead they let us all flounder around looking for an answer between us. It is more than likely they already know what is causing the problem and the solution to it. Apple: If they ignore us long enough, we will go away in frustration. These are some of the best engineering minds in the world and to believe for a moment they are unaware of the issue or the correct fix is simply not believable.

  • by webdanger,

    webdanger webdanger Feb 18, 2016 2:18 PM in response to Lagoiski
    Level 1 (4 points)
    Desktops
    Feb 18, 2016 2:18 PM in response to Lagoiski

    It happened even with an imac 5k. I toyed around with some other ram and reinstalled the OS from scratch, wiping the entire drive, and it didn't restart in two months.

     

    I have more imacs doing the random restarts and one had a bad thermal paste on so it was getting very hot and then restarted and the other was another ram related issue.

     

    its very hard to put a diagnostic on it when it happens randomly. I did not get and kernel panic attacks in my logs, except the one that kept restarted because of a bad ram.

  • by digitalkl,

    digitalkl digitalkl Feb 18, 2016 6:50 PM in response to webdanger
    Level 1 (4 points)
    Feb 18, 2016 6:50 PM in response to webdanger

    Yup mine is a late 2014 iMac 5k. Very intermittent but lately it got worse so I sent it in for repairs. One day had passed but the tech says nothing has happened yet.....duh!

     

    Btw mine is not restarting on its own but sudden power off. Cant get it to power on again until I pull the plug to reset SMC

     

    I already tried unplugging every night and it work great for 4 days. On the 5th day, it powered off 4 times in a short interval and another 4 times the next morning in short interval. I thought its broke for sure this time and took it in.

  • by krismanz,

    krismanz krismanz Feb 19, 2016 1:48 PM in response to digitalkl
    Level 1 (1 points)
    Feb 19, 2016 1:48 PM in response to digitalkl

    This is a one month update from my posts dated 1-8-16 at 10:48pm & 1-19-16 at 8:12pm.  After experiencing identical issues to everyone on this thread, the following parts were replaced by an Apple authorized technician on 1-19-16:

     

    Main logic board

    Power supply

    Power cord

    Hard Drive

     

    After 30 days, everything is working well with no shutdowns or issues, knock on wood.

     

    Now... after reading every single post on this thread since those dated May 2014, I have learned three important factors about this 2012 iMac and the shutdown problems:

     

    1. The issue is NOT the logic board or motherboard. If you only replace the logic board and nothing else, there is a 100% chance that you will be back for more repairs within days or weeks. When technicians make this recommendation (to only replace the logic board), ARGUE WITH THEM! and refer them to this thread. This many people from around the world can't be wrong!

    2. It is NOT an overheating issue or "excessive dust in the unit" problem. When my iMac was in the shop with the monitor removed, the technician noted that not a spec of dust was present anywhere in unit... and I own two cats and create as much dust as anyone.

    3. It probably IS an issue with the power supply or a component connected to the supply unit. Recently, several people have noted that a bad capacitor could be the culprit... this remains a possibility also.

     

    RECOMMENDATIONS:

     

    1. Don't waste time with Genius Bar test... this proves absolutely nothing when attempting to diagnose the issue.

    2. If the shutdown issue "can't be replicated" by an Apple technician, have them connect & re-connect devices to the USB ports in the back of the unit. Also, have them keep the machine powered on for several days and then put it under a stress test. Finally refer the Apple techniians to this thread. A good technician will not "ignore" this many people with the exact same iMac problem when this much evidence is present.

    3. Call Apple and report the issues before and after an Apple technician has a look. Just having Apple document your issue with your iMac serial number goes a long way even if you don't have the Apple Warranty.  Also, KEEP A DIARY of dates, times, events leading up to the shutdown. I did this in an earlier post and it was very valuable to both Apple technicians at the national database and my local repair people.

  • by Neovinter,

    Neovinter Neovinter Feb 26, 2016 3:39 AM in response to Lagoiski
    Level 1 (10 points)
    Feb 26, 2016 3:39 AM in response to Lagoiski

    I have the same model and I had the same problem. But now it does not exist for me.

    Just unplug your iMac from the outlet when not in use. I use a power strip with a switch for it.

    I do not know why it works, but it works. No crashes and sudden shutdowns for half a year.

    Hope this helps.

  • by Eddie Jasmine,

    Eddie Jasmine Eddie Jasmine Feb 26, 2016 3:17 PM in response to Lagoiski
    Level 1 (63 points)
    Feb 26, 2016 3:17 PM in response to Lagoiski

    This is a very long thread and it may have been addressed but...are you all recording the Previous Shutdown Cause from the Console?  You can do this by opening the Console app in your Applications > Utilities folder, going to it's search box and typing: previous shutdown. A number will be displayed.  If it is a hardware fault, it will be a negative number. A normal shutdown is registered as a 5.

     

    I think it's a good idea to do this because Apple doesn't publish the code descriptions anywhere but if you all list the code in your problem description, you may get an idea where the fault lies.  For example, I had an iMac that was randomly shutting down, particularly when the graphic's card was stressed.  However, I could immediately restart, no smc reset.  All the previous shutdown causes were labelled -128.  After doing extensive research, I concluded that this was a fault with the discrete graphics card.  I actually fixed my iMac through a process of reflowing my graphics card and reapplying the thermal paste/pads(Long story).  In the process of doing this, I also made sure that the connections on the graphics card were cleaned up AND that the pci-e slot on the logic board was also cleaned, thorougly, with a small scrapper tool and rubbing alcohol.  I was surprised at how much gunk was in the pci-e slot, which could explain power sensing problems causing shutdowns.  It would also explain why some people here may have their graphics cards replaced but the problem comes back later or vice-versa with the logic board.  There are two sides of the graphics system and you have to make sure that both are functioning properly.

     

    I've seen other codes from other users like -62 and such.  If you see 0 as a cause, that means that power was shutoff going to the computer, like someone pulled out the cord.  You might want to look at your outlet, UPS/powerstrip, cord and the power supply in the machine.  I haven't nailed down what the codes would be for faulty RAM, but I'll leave that up to you all. 

  • by Andrew_Debbie,

    Andrew_Debbie Andrew_Debbie Feb 28, 2016 9:20 AM in response to vanstar sydney
    Level 1 (4 points)
    Feb 28, 2016 9:20 AM in response to vanstar sydney

    Long overdue update.  We took our iMac in for repair in May 2015.   After keeping the computer long enough to reproduce the fault, they replace the logic board.   The iMac worked for for nearly a year. 

     

    Last week it started crashing again.   We have just a few days left on the three year warranty.   I have another Genius bar appointment.

     

    Looking obvious there is a hardware fault.  Probably the same components failed on the replacement board.

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